Safety-fuse.



PATENTED SEPT. 1, 1908.

J. SACHS. SAFETY FUSE. APPLICATION FILED MAY 18, 1907.

q-N E5 5 E5 Hi5 TTY UNITED sTAtrEs PATENT OEFICE.

JosEPn SACHS, OF HARTFORD, CONNECTICUT, AssIcNoR TO THE SACHS COMPANY,or HARTFORD, CON ECTICUT, A CORPORATION OF CONNECTICUT.

SAFETY-FUSE. I

Specification of Letters Patent.

Patented Sept. 1, 1908.

Application as May 18, 1907. Serial No. 374,415.

' To all whom it may concern:

Be it known that I, JOsEPH SACHS, a citizen of the United States,residing at Hartford, in the county of Hartford and State ofConnecticut, have invented an Improvement in Safety-Fuses, of which thefollowing is a specification.

My present invention relates to excess electric current protectivedevices or safety fuses, and the object thereof is the provision of anelectric safety fuse or protective device which is so constructed astorupture electric currents of large volume without an are or flash. I

Heretofore electro thermal protective devices have been provided inwhich a fusible conductor is inclosedin a casing of insulating materialand is surrounded by a filling material in a loose condition. In thesesocalled iuclosed fuses the arcing upon rupture of the fuse strip ischecked or eliminated due tothe fact that the gases or other products ofcombustion from the ruptured fuse strip are permitted to pass into andthough the interstices of the filling surrounding the fuse strip and arethus broken up and cooled with the resultant loss of disruptive pressureand breaking up of the are. As heretofore constructed however, eachinclo'sed fuse device is a self-contained structure and therefore afterbeing ruptured must be returned to the manufacturer for the )urpose ofbeing properly re-loaded and re-filled, and moreover as it is difficultto construct such inclosed safety fuse devices with very large amperecapacities without using tubes or casings and other parts of largedimensions, the re-loading or re-filling of such safety fuse devices isnecessarily relatively expensive.

The safety fuse or electric current protect ive device comprising mypresent invention is ofthe thermal type, that is to say, its operationdepends on the heating and fusing of a conductor, and I am enabled bythe peculiar construction and combination of elements which I employ toproduce a safety fuse in which the rupture of the fusible element ispractically'free from' are and consequently 1n the employment of thisdevice the circuit even at large current values may be openedpractically without an arc and at the same time the structure is suchthat the destructible element of this improved safety fuse may bereadily and inexpensively renewed.

As is well understood, the arcing in an electric circuit is dependentupon the conduction of the media etween the separated electrodes, andthat if it were possible to practically eliminate the separation ofminute particles of the conductor material from the electrode points atthe instant of initial rupture, or if it were possible to reduce theamount of metal in each of the separated electrodes to a mimimum, theresultant arcing would be eliminated or reduced proportionately. Forexample, when a single fusible conductor carrying say 1000 amperes isruptured due to an excess current, the arcing is exceedingly severebecause Of the large amount of metal acted upon by the current andbetween which the arc is formed. Should however, 1000 conductors betaken, each capable of carrying one ampere and each separated from theothers by a suitable insulating medium, the arcing upon the ru ture ofsuch a multiple fuse device would e very muclr reduced in view of thefact that ingly reduced conducting material, and furthermore, if ach ofthese one ampere fusible conductors were independently located in aninsulating sheath into which they were tightly fitted and under tension,upon the rupture of the fusible conductors each one would be pulledasunder and out of the hole or recess in the insulating sheath and thearcs created u on rupture would be further reduced or e iminated, due tothe fact that they could not follow through the very small apertureafter the fusible conductors were withdrawn.

In carrying out my present invention, I preferably employ a sheathing ofinsulating material, a pair of electrodes between which the saidsheathing of insulating material is located, a multiplicity of fusibleconductors connected to and extending between the said electrodes andpassing through the said sheathing, terminals connected respectively tothe said electrodes and means for effecting a tension on said conductorsto draw the separated portions of the same apart immediately upon beingdisrupted, as will be hereinafter more particularly described.

In the drawing, Figure 1 is an elevation of the safety fuse comprisingmy present invention. Fig. 2 is a plan and partial section, the sectionbeing taken on line y, y, Fig. 1. Fig.

the others.

3 is a central section of an inclosed safety fuse comprising my presentin- Fig el is an end view of the fuse.

vention. device shown inFig. 3 and Fig. 5 is asection taken at line as,x, of Fig. 3.

Referring to the drawing and particularly to Figs. 1 and 2, a designatesa sheathing par titionwhich is preferably made of asbestos sponge, orother similar suitable insulating material having the requisite elasticproperties to efiect the purpose and perform the function of thiselement of my present invention. I) c designate electrodes made of anysuitable conductive material and preferably provided centrally withscrew threaded stud members 10 11 respectively. Extending be tween theelectrodes 6 c and electrically connected therewith and passing throughthe sheathing partition a I employ a multiplicity of fusible conductorsindicated at f. As will be understood, these fusible conductors may bemade of any suitable material and in pass ing through the said sheath 0.each one of the same is independently insulated from all of (irepresents a head adapted to be connected to. the electrode b by beingscrewed down on the stud 10, and similarly e is a head adapted to beelectrically connected to anelectrode c by being screwed down on thestud 11; d e 'are helical springs, re

. spectively connected at one end with the head members (i e and at theopposite ends. "with terminals (Z 6 respectively. The terminals d 0 maybe of any desired construction'and are adapted to be connected toterminals d e mounted on a suitable base a, and the sheathing ofinsulating material a of relatively large dimensions is preferablysecured to this base a by pins a being passed through the sheathing andmade fast in the said base in any desired manner.

It will be understood that the hereinbefore described protective deviceis secured to the base with the spring members under tension and thatimmediately upon the fusible conductors being disrupted the se aratedparts of each conductor will be entirely withdrawn from the sheathingpartition by the action of the springs in drawing apart the saidelectrodes, and that the are formed by the blowing of each conductorcannot follow not only because of the smallness of the aperture in whicheach conductor is insulated, but because on account of the elasticnature of the sheathing partition; the apertures in which theC'ldUCtOI'S normally he will be self closing immediately upon thewithdrawal of the fusible conductors.

trated my present invention as embodied in an inclosed fuse device, grepresents the easing made of fiber or other insulating material as iscustomary, and preferably tubular. The ends of the casing g are providedwith end caps 7 adapted to fit over the extremities thereof and to. besecured thereon by meansof set screws 12 or otherwise. Centrally eachend-ca -h isprovided with an inwardly extending s 'ghtly conical ortapering wall indicated at '1', and this wall i terminates in aninternal flange indicated at k and provided with a central openingthrough which either the terminal (1 or the terminal 0 may be passed.

In providing the destructible element of the fuse device according to mypresent invention, in an inclosed fuse device, I prefer to em loy atubular lining 13 fitting closely wit the tubular casing g and a diskwhich may also be made of insulating material indicated at 14; the disk14 being adapted 'to abut against the inner face of the flange 76 ofeach end cap it and the tubular lining 13 to extend between the disk 14and the sheath member 7 a, to maintain the same, together with the partsconstituting the destructible element, in a fixed positionwithin thecas- II? this structure as illustrated, I prefer to provide theterminals (1 e with head members 15 16 respectively, which are of such adiameter as to create a slight wedge action in being passed into therecess formed by the conical walls 1, and within the conical wall 71 ofeach each fusible conductor member be inter rupted and broken by notbeing able to follow the parted conductor memberout of the sheathing,but the sheathing being made of insulating material of a spongyconsistency will from its elasticity close the hole or space formerlyoccupied by a fusible conductor and thereby insure the extinguishing ofany are which is formed in the rupture of the fusible members.

I claim as my invention: 1

1. A safety fuse comprising a plurality of separately insulated andsheathed conductors connected in multiple to common electrodes, andmeans for effecting a tension to separate the said conductorsimmediately l upon the same becoming disrupted. Referring to Fig. 3wherein I have illus- 2. A safety-fuse comprisinga plurality ofconductors, electrodes common to all of said conductors, a sheathingpartition between the said electrodes and in which the said consaidconductors and theelectrodes immedi-' ately upon the said conductorsbecoming disrupted.

3. A safety fuse comprising a plurality of conductors, electrodes commonto all of the said conductors, a stationary sheathing partition ofsuitable and insulating material between the said electrodes and throughwhich each of the said conductors passes and means for effecting atension to separate the said electrodes immediately upon the conductorsbecoming disrupted to entirely withdraw the parted ortions of the saidconductors from the sai sheathing partition.

4. A safety fuse'comprising a casing, end caps therefor and a sheathmember within said casing, electrodes on the opposite sides of saidsheath, fusible conductors connected to the said electrodes extendingbetween the same and passing through the said sheathing, means forconnecting the said electrodes with the said end caps, means formaintaining the said sheathing in position within the said casing andmeans for moving the said elec trodes away from one another immediatelyupon the rupture of the said conductors.

5. A safety fuse comprising a casing, end caps therefor and a sheathmember within said casing, electrodes on the opposite sides of saidsheathing, fusible conductors connected to the said electrodes extendingbetween the same and passing through the said sheathing, means forconnecting the said electrodes with the said end caps, and means forcreating a tension on the said. fusible conductors.

6. A safety fuse comprising a casing, end caps therefor, an inwardlyextending wall in each of the said endcaps, an internal flange at theinner end of each of the said walls, a sheathing, electrodes on theopposite sides of the said sheathing, terminals connected with,

each of the said electrodes and adapted to pass through the flanges atthe inner extremities of the said inwardly extending walls and tomake'electrical connection with the said end caps, a plurality offusible conductors each electrically connected with the said electrodesand passing through and insulated in said sheathing and means for movingone electrode and its terminal from the other electrode and its terminalimmediately upon the rupture of the said fusible conductors to entirelywithdraw the parted portions of the same from the said sheathing.

7. A safety fuse comprising a tubular cas ing, end caps therefor, aninwardly extending wall in each of said end caps, a flange at the innerextremity of each of the said inwardly extending walls, a sheathing,electrodes on the opposite sides of the said sheathing, a multiplicityof fusible conductors connected to the said electrodes extending betweenthe same and passing through the said sheathing, terminals electricallyconnected to the said electrodes and adapted to pass through the saidflanges at the inner ends of the said inwardly extending walls of theend caps, a head at the outer end of each of the said terminals adaptedto enter and contact with the side of the recess formed by the saidinwardly extending walls, and springs extending between the said head ofthe terminal and the said flanges at the inner ends of the said inwardlyextending walls.

8. A safety fuse comprising a tubular casing, end caps therefor, aninwardly extending wall entering each of said end caps, a flange at theinner extremity of each of the said inwardly extending walls, asheathing, electrodes on the opposite sides of the said sheathing, amultiplicity of fusible conductors con-' nected to the said electrodesextending between the same and passing through the said sheathing,terminals electrically connected to the said electrodes and adapted topass through the said flanges at the inner ends of the said inwardlyextending walls of the end caps, a head at the outer end of each of thesaid terminals adapted to enter and contact with the sides of the recessformed by the said inwardly extending walls, springs extending betweenthe sald heads of the terminals and the said flanges at the inner endsof the said inwardly extending walls, a disk of insulating materialsurrounding each of the said terminals and adapted to abut against theflange of the adjacent end cap and a cylindrical lining adapted to fitwithin the said casing, and to extend between the said insulating diskmembers and the said sheath.

Signed -by me this 12th day of April 1907.

JOSEPH SACHS.

' Witnesses:

" GEo. T. PINGKNEY,

E. ZACHARIASEN.

